The present invention pertains to improvements in the field of wound care. More particularly, the invention relates to a wound closure system for closing a wound on a patient.
When closing a wound, it is necessary to join and keep together the facing edges of the wound. If the separated skin sections are sewn, unesthetical scars may remain, and if they are stapled, such scars generally remain.
Cyanoacrylate-based adhesives have been suggested as an alternative to sutures. When a cyanoacrylate adhesive is employed, the separated skin sections are joined and the adhesive is applied on top of the joined sections under sterile conditions. The cyanoacrylate adhesive bonds to the skin and polymerizes so as to keep together the joined sections. Although cyanoacrylate adhesives successfully bind the skin, the use of such adhesives as suture replacements can be accompanied by occasional adhesion failure resulting in wound reopening which requires closure by sutures. Fear of wound reopening is one of the reasons physicians have been reluctant to use any adhesive including cyanoacrylate based adhesives instead of sutures.
U.S. Pat. No. 5,254,132 proposes a method of treating suturable wounds by first suturing or stapling the wound and then joining the skin between sutures or staples with a cyanoacrylate adhesive. According to this method, the wound is sutured or stapled so that the sutures or staples are separated from each other by no more than about 1.2 centimeter and no less than about 0.6 centimeter. Butyl 2-cyanoacrylate is then applied to the opposing and still separated skin sections between the sutures or staples in an amount sufficient so that upon polymerization the skin sections are joined; the application is conducted so that contact of the cyanoacrylate adhesive with the sutures or staples is avoided. The adjacent separated skin sections are thereafter contacted under conditions that permit the adhesive to polymerize so as to join the separated skin sections. Such a method is not only time-consuming and requires particular skill to practice, but also delays healing of the wound if cyanoacrylate adhesive penetrates in between the skin sections.
Surgical adhesive strips for closing wounds are also known. These strips generally do not have much tensile strength so that their use is limited to shallow wounds requiring little tension to close. Another major disadvantage resides in their permeability to water, causing the strips to become unstuck upon contact with water or moisture and thereby preventing the wounded area from being washed.
U.S. Pat. No. 5,259,835 discloses a wound closure device that employs a porous bonding member adapted to receive a flowable moisture-curable surgical adhesive. The bonding member is positioned by a carrier member which is used to achieve initial apposition of the wound and which may later be removed. Since the adhesive flows into the bonding member and the latter serves as a matrix for the adhesive, the bonding member becomes rigid as the adhesive therein undergoes curing so that it looses flexibility. Part of the surgical adhesive also flows through the bonding member and may enter into the wound.
It is therefore an object of the present invention to overcome the above drawbacks and to provide a wound closure system for closing wounds.
In accordance with the invention, there is provided a wound closure system for closing a wound on a patient, comprising:
an elongated, flexible backing strip having opposite ends, first and second surfaces facing away from one another and a length and width sufficient to secure facing edges of the wound in close juxtaposition to one another, the backing strip comprising a first portion disposed between the ends and adapted to overlie the facing edges of the wound, and second and third portions disposed on either side of the first portion and each provided with a predetermined number of spaced-apart apertures extending through the backing strip from one surface thereof to the other, the first portion being free of any such aperture;
a first pressure-sensitive adhesive coated on at least part of the first surface of the backing strip including the second and third portions thereof, to adhere at least the second and third portions of the, backing strip to the patient with the facing edges of the wound being in close juxtaposition;
a first protective member removably attached to the backing strip and covering the pressure-sensitive adhesive; and
a flowable, moisture-curable surgical adhesive for application into the apertures to strengthen the adhesion of the second and third portions of the backing strip to the patient.
After removal of the protective member to expose the pressure-sensitive adhesive, application of the backing strip with the exposed pressure-sensitive adhesive onto the patient to secure the facing edges of the wound in close juxtaposition and application of the surgical adhesive into the apertures, the surgical adhesive flows through the apertures and upon curing forms discrete bonding sites cooperating with the backing strip to maintain the facing edges of the wound in close juxtaposition without the cured adhesive adversely affecting the flexibility of the backing strip.
Applicant has found quite unexpectedly that by using a flexible backing strip having a non-perforated first portion disposed between the ends thereof and perforated second and third portions disposed on either side of the first portions, and a pressure-sensitive adhesive coated on at least part of the first surface of the backing strip including the second and third portions thereof, and applying a flowable, moisture-curable surgical adhesive into the apertures or perforations defined in the second and third portions, after application of the backing strip with the exposed pressure-sensitive adhesive onto the patient to secure the facing edges of the wound in close juxtaposition, the surgical adhesive flows through the apertures and upon curing forms discrete bonding sites strengthening the adhesion of the second and third portions of the backing strip to the patient and cooperating with the backing strip to maintain the facing edges of the wound in close juxtaposition without the cured adhesive adversely affecting the flexibility of the backing strip. Since the surgical adhesive is applied on either side of the first portion of the backing strip which overlies the facing edges of the wound, the surgical adhesive does not enter into the wound so that healing of the wound is not delayed. On the other hand, since the flexibility of the backing strip is not adversely affected by the cured adhesive, the strip remains flexible and can thus follow movements of the skin.
Preferably, the backing strip comprises a sheet of polymer such as polyurethane or nylon. It can also comprise a web of fabric material such as cotton, rayon, acrylic or polyester fibers. The protective member, on the other hand, preferably comprises a film of high density polyethylene or a sheet of wax paper.
According to a preferred embodiment of the invention, the apertures are perforations having a circular cross-section with a diameter ranging from 0.5 to 3 mm, preferably from 1 to 2 mm. For a backing strip with the first or second surface thereof defining an area of about 12 cm , the number of perforations defined in each of the second and third portions can vary between 4 and 20, and preferably ranges from 8 to 12. Preferably, a second protective member having a second pressure-sensitive adhesive coated on one side thereof is removably attached to the backing strip and covers the second surface thereof, the strip being disposed between the first and second protective members. The second protective member is provided with a corresponding number of perforations registering with the perforations defined in the second and third portions of the backing strip, and being in flow communication therewith. The provision of such a second protective member prevents the surgical adhesive from contacting the second surface of the backing strip during its application so that when the second protective member together with the second pressure-sensitive adhesive are removed from the backing strip following application of the surgical adhesive, there is no surgical adhesive on the second surface, which upon curing could adversely affect the flexibility of the backing strip. The second protective member preferably comprises a film of low density polyethylene. Instead of using a second pressure-sensitive adhesive, it is also possible to removably attach the second protective member to the backing strip by heat or pressure application.
According to another preferred embodiment, the second and third portions of the backing strip each have an end edge and a pair of opposite side edges, and the apertures are U-shaped notches defined along the side and end edges of each of the second and third portions. Preferably, a removable second protective member similar to the one described above, but having perforations registering with the notches and being in flow communication therewith, covers the second surface of the backing strip.
According to a further preferred embodiment, the second and third portions of the backing strip are each provided with at least one fold line extending transversely of the strip between the apertures to increase the flexibility of the backing strip.
According to yet another preferred embodiment, the second and third portions of the backing strip are each provided with a plurality of spaced-apart anchoring elements disposed between the apertures and projecting outwardly from the first surface. These anchoring elements assist in securing the facing edges of the wound in close juxtaposition.